This article argues that it is possible to bring the social sciences into evolutionary focus without being committed to a thesis the author calls ontological reductionism, which is a widespread predilection for lower-level explanations. After showing why we should reject ontological reductionism, the author argues that there is a way to construe cultural evolution that does justice to the autonomy of social science explanations. This paves the way for a liberal approach to explanation the author calls explanatory pluralism, which allows for the possibility of explaining cultural phenomena in terms of different evolutionary processes. Key Words: cultural evolution  reductionism  explanatory pluralism  evolutionary psychology.